Struct bevy::hierarchy::Parent

pub struct Parent(/* private fields */);

Holds a reference to the parent entity of this entity. This component should only be present on entities that actually have a parent entity.

Parent entity must have this entity stored in its Children component. It is hard to set up parent/child relationships manually, consider using higher level utilities like BuildChildren::with_children.

See HierarchyQueryExt for hierarchy related methods on Query.

Implementations

impl Parent

pub fn get(&self) -> Entity

Gets the Entity ID of the parent.

Examples found in repository

examples/ui/ui.rs (line 355)

fn mouse_scroll(
    mut mouse_wheel_events: EventReader<MouseWheel>,
    mut query_list: Query<(&mut ScrollingList, &mut Style, &Parent, &Node)>,
    query_node: Query<&Node>,
) {
    for mouse_wheel_event in mouse_wheel_events.read() {
        for (mut scrolling_list, mut style, parent, list_node) in &mut query_list {
            let items_height = list_node.size().y;
            let container_height = query_node.get(parent.get()).unwrap().size().y;

            let max_scroll = (items_height - container_height).max(0.);

            let dy = match mouse_wheel_event.unit {
                MouseScrollUnit::Line => mouse_wheel_event.y * 20.,
                MouseScrollUnit::Pixel => mouse_wheel_event.y,
            };

            scrolling_list.position += dy;
            scrolling_list.position = scrolling_list.position.clamp(-max_scroll, 0.);
            style.top = Val::Px(scrolling_list.position);
        }
    }
}

examples/animation/gltf_skinned_mesh.rs (line 56)

fn joint_animation(
    time: Res<Time>,
    parent_query: Query<&Parent, With<SkinnedMesh>>,
    children_query: Query<&Children>,
    mut transform_query: Query<&mut Transform>,
) {
    // Iter skinned mesh entity
    for skinned_mesh_parent in &parent_query {
        // Mesh node is the parent of the skinned mesh entity.
        let mesh_node_entity = skinned_mesh_parent.get();
        // Get `Children` in the mesh node.
        let mesh_node_children = children_query.get(mesh_node_entity).unwrap();

        // First joint is the second child of the mesh node.
        let first_joint_entity = mesh_node_children[1];
        // Get `Children` in the first joint.
        let first_joint_children = children_query.get(first_joint_entity).unwrap();

        // Second joint is the first child of the first joint.
        let second_joint_entity = first_joint_children[0];
        // Get `Transform` in the second joint.
        let mut second_joint_transform = transform_query.get_mut(second_joint_entity).unwrap();

        second_joint_transform.rotation =
            Quat::from_rotation_z(FRAC_PI_2 * time.elapsed_seconds().sin());
    }
}

examples/tools/scene_viewer/animation_plugin.rs (line 111)

fn assign_clips(
    mut players: Query<&mut AnimationPlayer>,
    targets: Query<(Entity, &AnimationTarget)>,
    parents: Query<&Parent>,
    scene_handle: Res<SceneHandle>,
    clips: Res<Assets<AnimationClip>>,
    gltf_assets: Res<Assets<Gltf>>,
    assets: Res<AssetServer>,
    mut graphs: ResMut<Assets<AnimationGraph>>,
    mut commands: Commands,
    mut setup: Local<bool>,
) {
    if scene_handle.is_loaded && !*setup {
        *setup = true;
    } else {
        return;
    }

    let gltf = gltf_assets.get(&scene_handle.gltf_handle).unwrap();
    let animations = &gltf.animations;
    if animations.is_empty() {
        return;
    }

    let count = animations.len();
    let plural = if count == 1 { "" } else { "s" };
    info!("Found {} animation{plural}", animations.len());
    let names: Vec<_> = gltf.named_animations.keys().collect();
    info!("Animation names: {names:?}");

    // Map animation target IDs to entities.
    let animation_target_id_to_entity: HashMap<_, _> = targets
        .iter()
        .map(|(entity, target)| (target.id, entity))
        .collect();

    // Build up a list of all animation clips that belong to each player. A clip
    // is considered to belong to an animation player if all targets of the clip
    // refer to entities whose nearest ancestor player is that animation player.

    let mut player_to_graph: EntityHashMap<(AnimationGraph, Vec<AnimationNodeIndex>)> =
        EntityHashMap::default();

    for (clip_id, clip) in clips.iter() {
        let mut ancestor_player = None;
        for target_id in clip.curves().keys() {
            // If the animation clip refers to entities that aren't present in
            // the scene, bail.
            let Some(&target) = animation_target_id_to_entity.get(target_id) else {
                continue;
            };

            // Find the nearest ancestor animation player.
            let mut current = Some(target);
            while let Some(entity) = current {
                if players.contains(entity) {
                    match ancestor_player {
                        None => {
                            // If we haven't found a player yet, record the one
                            // we found.
                            ancestor_player = Some(entity);
                        }
                        Some(ancestor) => {
                            // If we have found a player, then make sure it's
                            // the same player we located before.
                            if ancestor != entity {
                                // It's a different player. Bail.
                                ancestor_player = None;
                                break;
                            }
                        }
                    }
                }

                // Go to the next parent.
                current = parents.get(entity).ok().map(|parent| parent.get());
            }
        }

        let Some(ancestor_player) = ancestor_player else {
            warn!(
                "Unexpected animation hierarchy for animation clip {:?}; ignoring.",
                clip_id
            );
            continue;
        };

        let Some(clip_handle) = assets.get_id_handle(clip_id) else {
            warn!("Clip {:?} wasn't loaded.", clip_id);
            continue;
        };

        let &mut (ref mut graph, ref mut clip_indices) =
            player_to_graph.entry(ancestor_player).or_default();
        let node_index = graph.add_clip(clip_handle, 1.0, graph.root);
        clip_indices.push(node_index);
    }

    // Now that we've built up a list of all clips that belong to each player,
    // package them up into a `Clips` component, play the first such animation,
    // and add that component to the player.
    for (player_entity, (graph, clips)) in player_to_graph {
        let Ok(mut player) = players.get_mut(player_entity) else {
            warn!("Animation targets referenced a nonexistent player. This shouldn't happen.");
            continue;
        };
        let graph = graphs.add(graph);
        let animations = Clips::new(clips);
        player.play(animations.current()).repeat();
        commands
            .entity(player_entity)
            .insert(animations)
            .insert(graph);
    }
}

pub fn as_slice(&self) -> &[Entity]

Gets the parent Entity as a slice of length 1.

Useful for making APIs that require a type or homogeneous storage for both Children & Parent that is agnostic to edge direction.

Methods from Deref<Target = Entity>

pub const PLACEHOLDER: Entity = _

Trait Implementations

impl Component for Parent

where Parent: Send + Sync + 'static,

const STORAGE_TYPE: StorageType = bevy_ecs::component::StorageType::Table

A constant indicating the storage type used for this component.

fn register_component_hooks(_hooks: &mut ComponentHooks)

Called when registering this component, allowing mutable access to its ComponentHooks.

impl Debug for Parent

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Deref for Parent

type Target = Entity

The resulting type after dereferencing.

fn deref(&self) -> &<Parent as Deref>::Target

Dereferences the value.

impl FromReflect for Parent

where Parent: Any + Send + Sync, Entity: FromReflect + TypePath + RegisterForReflection,

fn from_reflect(reflect: &(dyn Reflect + 'static)) -> Option<Parent>

Constructs a concrete instance of Self from a reflected value.

fn take_from_reflect( reflect: Box<dyn Reflect> ) -> Result<Self, Box<dyn Reflect>>

Attempts to downcast the given value to Self using, constructing the value using from_reflect if that fails.

impl FromWorld for Parent

fn from_world(_world: &mut World) -> Parent

Creates Self using data from the given World.

impl GetTypeRegistration for Parent

where Parent: Any + Send + Sync, Entity: FromReflect + TypePath + RegisterForReflection,

fn get_type_registration() -> TypeRegistration

Returns the default TypeRegistration for this type.

fn register_type_dependencies(registry: &mut TypeRegistry)

Registers other types needed by this type.

impl MapEntities for Parent

fn map_entities<M>(&mut self, entity_mapper: &mut M)

where M: EntityMapper,

Updates all Entity references stored inside using entity_mapper.

impl PartialEq for Parent

fn eq(&self, other: &Parent) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Reflect for Parent

where Parent: Any + Send + Sync, Entity: FromReflect + TypePath + RegisterForReflection,

fn get_represented_type_info(&self) -> Option<&'static TypeInfo>

Returns the TypeInfo of the type represented by this value.

fn into_any(self: Box<Parent>) -> Box<dyn Any>

Returns the value as a Box<dyn Any>.

fn as_any(&self) -> &(dyn Any + 'static)

Returns the value as a &dyn Any.

fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Returns the value as a &mut dyn Any.

fn into_reflect(self: Box<Parent>) -> Box<dyn Reflect>

Casts this type to a boxed reflected value.

fn as_reflect(&self) -> &(dyn Reflect + 'static)

Casts this type to a reflected value.

fn as_reflect_mut(&mut self) -> &mut (dyn Reflect + 'static)

Casts this type to a mutable reflected value.

fn clone_value(&self) -> Box<dyn Reflect>

Clones the value as a Reflect trait object.

fn set(&mut self, value: Box<dyn Reflect>) -> Result<(), Box<dyn Reflect>>

Performs a type-checked assignment of a reflected value to this value.

fn apply(&mut self, value: &(dyn Reflect + 'static))

Applies a reflected value to this value.

fn reflect_kind(&self) -> ReflectKind

Returns a zero-sized enumeration of “kinds” of type.

fn reflect_ref(&self) -> ReflectRef<'_>

Returns an immutable enumeration of “kinds” of type.

fn reflect_mut(&mut self) -> ReflectMut<'_>

Returns a mutable enumeration of “kinds” of type.

fn reflect_owned(self: Box<Parent>) -> ReflectOwned

Returns an owned enumeration of “kinds” of type.

fn reflect_partial_eq(&self, value: &(dyn Reflect + 'static)) -> Option<bool>

Returns a “partial equality” comparison result.

fn reflect_hash(&self) -> Option<u64>

Returns a hash of the value (which includes the type).

fn debug(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Debug formatter for the value.

fn serializable(&self) -> Option<Serializable<'_>>

Returns a serializable version of the value.

fn is_dynamic(&self) -> bool

Indicates whether or not this type is a dynamic type.

impl TupleStruct for Parent

where Parent: Any + Send + Sync, Entity: FromReflect + TypePath + RegisterForReflection,

fn field(&self, index: usize) -> Option<&(dyn Reflect + 'static)>

Returns a reference to the value of the field with index index as a &dyn Reflect.

fn field_mut(&mut self, index: usize) -> Option<&mut (dyn Reflect + 'static)>

Returns a mutable reference to the value of the field with index index as a &mut dyn Reflect.

fn field_len(&self) -> usize

Returns the number of fields in the tuple struct.

fn iter_fields(&self) -> TupleStructFieldIter<'_>

Returns an iterator over the values of the tuple struct’s fields.

fn clone_dynamic(&self) -> DynamicTupleStruct

Clones the struct into a DynamicTupleStruct.

impl TypePath for Parent

where Parent: Any + Send + Sync,

fn type_path() -> &'static str

Returns the fully qualified path of the underlying type.

fn short_type_path() -> &'static str

Returns a short, pretty-print enabled path to the type.

fn type_ident() -> Option<&'static str>

Returns the name of the type, or None if it is anonymous.

fn crate_name() -> Option<&'static str>

Returns the name of the crate the type is in, or None if it is anonymous.

fn module_path() -> Option<&'static str>

Returns the path to the module the type is in, or None if it is anonymous.

impl Typed for Parent

where Parent: Any + Send + Sync, Entity: FromReflect + TypePath + RegisterForReflection,

fn type_info() -> &'static TypeInfo

Returns the compile-time info for the underlying type.

impl Eq for Parent

impl StructuralPartialEq for Parent